BTW, I could design electronic suspension of key for you. It may not cheap, but you'll avoid any patent issues.

Usually, schemes are copyrighted, or even patented.

If you will just make 1-2 copies for your internal use, most probably nothing happen, because in legal practice exists negligible case, where not worth considering sue you.

But if you will show copies on public, upload 3d model on your site, and/or try to sell them (make ads, other marketing, and yes, opensource copy of patented things also prohibited), on some moment they could make decision, this is not negligible and will sue you.

To avoid such things, you could try to find their patents and make your own mechanics with other geometry.

Also, patents are not forever, usual max term approx, up to 70 years, and than it become effectively public domain.

So you could copy mechanics of some old piano, or expired patent.